# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Cottonwood Canyon (Lassen County)
Water Body ID: | CAR6374002420080811153949
Water Body Type: | River & Stream

DECISION ID | 27393 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Fecal Coliform
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. One of two samples exceeded the objective and one was an estimate and cannot be used in assessment. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 or Table 3.2 of the Policy. 3. One of two samples exceeded the objective and the other sample is an estimate and cannot be assessed using Table 3.2 of the listing policy. This does not exceed the allowable frequency in Table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 27393, Fecal Coliform | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 26133
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. One of two fecal coliform samples had a count of 401 colonies per mL and the other had colonies "too numerous to count." (Because the objective requires a minimum of five samples in a 30-day period, a log mean was not calculated.)
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Two stations were sampled.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 27393, Fecal Coliform | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 26060
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 2
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. One of two fecal coliform samples had a count of 401 colonies per mL and the other had colonies "too numerous to count." (Because the objective requires a minimum of five samples in a 30-day period, a log mean was not calculated.)
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 26554 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Nitrate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the California Maximum Contaminant Level (MCL). No biological data are available to assess compliance with the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample does not exceed the MCL and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. No biological data are available for assessment of compliance with the objective for biostimulatory substances. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 26554, Nitrate | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6629
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled Cottonwood Canyon on July 25, 2002. One sample was analyzed for NO3-N. The concentration was 0.26 mg/L. No data on algae or macrophytes were available for assessment of compliance with the biostimulatory substances objective.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | There are no site specific numerical objectives for nitrogen for this stream. The Lahontan Basin Plan's regionwide narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled.
Temporal Representation: | One sample was collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 26554, Nitrate | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6623
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled Cottonwood Canyon on July 25, 2002. One sample was analyzed for NO3-N. The concentration was 0.26 mg/L. The MCL was not exceeded.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrate is 45 mg/L expressed "as nitrate", equivalent to 10 mg/L expressed "as N."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled.
Temporal Representation: | One sample was collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 27665 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the two samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 27665, Oxygen, Dissolved | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6615
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. Two samples had dissolved oxygen concentrations of 6.95 and 6.82 mg/L. . The objective was not violated.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The water quality objective, from Lahontan Basin Plan Table 3-6, is a 1-day minimum dissolved oxygen concentration of 4 mg/L..
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 27666 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Phosphate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. No biological data are available to determine whether the single sample exceeds the water quality objective for biostimulatory substances. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. No biological data are available to determine whether the single phosphate sample exceeds the water quality objective. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 27666, Phosphate | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6632
Pollutant: | Phosphate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled Cottonwood Canyon on July 25, 2002. One sample was analyzed for PO4-P The concentration was 0.0.39 mg/L. No data on algae or macrophytes were available for assessment of compliance with the biostimulatory substances objective.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | There are no site specific numerical objectives for phosphorus for this stream. The Lahontan Basin Plan's regionwide narrative objective for biostimulatory substances states: "Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled.
Temporal Representation: | One sample was collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 19895 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Sediment
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: One line of evidence is available in the administrative record to assess this pollutant. The water quality objective for sediment is antidegradation based. The two available samples cannot be used to document baseline and trend conditions to assess compliance with the objective using Listing Policy section 3.10. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The two available samples are insufficient to assess compliance with the objective under section 3.10 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 19895, Sediment | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 26059
Pollutant: | Sediment
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. The concentrations of suspended sediment in two samples were 134 and 56.2 mg/L.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's narrative objective states: "The suspended sediment load and suspended sediment discharge rate of surface waters shall not be altered in such a manner as to cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 27612 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Specific Conductance
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Neither of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not the data quantity requirements of section 6.1.5 of the Policy. 3. Neither of two samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 27612, Specific Conductance | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6606
Pollutant: | Specific Conductance
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. The specific conductance values in two samples (reported as "EC") were 172 and 208 uS/cm. The MCL was not exceeded.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 18177 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: One line of evidence is available in the administrative record to assess this pollutant. The Lahontan Basin Plan's temperature objective is antidegradation-based and the available data are insufficient to document baseline and trend conditions as required by section 3.10 of the Listing Policy. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The two available samples are insufficient to determine compliance with the objective under seciton 3.10 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 18177, Temperature, water | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6616
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. Water temperatures in two samples were 16.22 and 16.54 degrees Celsius.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The applicable language from the Lahontan Basin Plan's temperature objective is: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction fo the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 28394 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Total Coliform
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. It cannot be determined whether the total coliform count reflects natural or anthropogenic sources. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The source of the total coliform bacteria cannot be determined and compliance with the objective cannot be assessed using Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 28394, Total Coliform | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 27980
Pollutant: | Total Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled Cottonwood Canyon on July 25, 2002. One total coliform sample had a count of 401 colonies per mL.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled.
Temporal Representation: | One sample was collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 27397 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | Turbidity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Two lines of evidence are available in the administrative record to assess this pollutant. The single sample exceeded the Maximum Contaminant Level (MCL). The narrative water quality objective for turbidity is an antidegradation-based objective and the single sample is insufficient to document baseline and trend conditions as required under Listing Policy Section 3.10. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The single sample exceeded the MCL and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.(The minimum sample number requirements of Table 3.2 are not met.) 4. The requirements of Listing Policy section 3.10 to document baseline and trend conditions are not met in relation to the narrative water quality objective. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 27397, Turbidity | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6640
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled Cottonwood Canyon on July 25, 2002. One turbidity measurement was 21.1 NTU. The MCL was exceeded.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for turbidity is 5 NTU.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled.
Temporal Representation: | One sample was collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 27397, Turbidity | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6635
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled Cottonwood Canyon on July 25, 2002. One turbidity measurement was 21.1 NTU.
Data Reference: | Title 40. Chapter 1. Section 143.3. Code of Federal Regulations. Secondary Maximum Contaminant Levels
| Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's water quality objective states: "Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10 percent."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station was sampled.
Temporal Representation: | One sample was collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):

DECISION ID | 30067 | Region 6
Cottonwood Canyon (Lassen County)

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: Two lines of evidence is available in the administrative record to assess this pollutant. The water quality objective for pH is antidegradation based and the available data are insufficient to document baseline and trend conditions as required by section 3.10 of the Listing Policy. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used do not satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. The two available samples cannot be used to document baseline and trend conditions under the requirements of Listing Policy section 3.10. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains in same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 30067, pH | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 26061
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. The pH values in two samples were 8.35 and 7.9 units.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's regionwide objective for pH states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 30067, pH | Region 6
Cottonwood Canyon (Lassen County)
LOE ID: | 6607
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Bureau of Land Management sampled two stations in Cottonwood Canyon on July 25, 2002. Two samples had pH values of 8.35 and 7.9 units.
Data Reference: | Water quality data for surface waters on U.S Bureau of Land Management lands in Lassen and Modoc Counties
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's regionwide objective for pH states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at two different stations.
Temporal Representation: | Two samples were collected on July 25, 2002.
Environmental Conditions: | Cottonwood Canyon flows from the mountains east of Eagle Lake to Creamer Reservoir, south of Horse Lake in Lassen County. As a minor surface water of the Snowstorm Mountain Hydrologic Area, it has categorically designated beneficial uses. No site-specific water quality objectives have been established for this creek.
QAPP Information: | No quality assurance information was submitted with the data.
QAPP Information Reference(s):